One typical application of the mobile multimedia broadcast technology is mobile TV service, which can exploit the network capability to the largest extent by providing plenty services as far as the mobile operators are concerned; and the mobile TV service is a new channel of TV broadcast which can fully take advantage of the content resource and extend the user scope so as to achieve the mobility of the broadcasting network as far as the broadcasters are concerned. In 2006, the number of cell phone subscribers in China has been close to 400,000,000, and the number of families having televisions has reached about 350,000,000. It can be imagined that the mobile TV service as a product of the combination of cell phone service and TV service will created a huge consumer market. According to the predication of foreign countries, there will be 120,000,000 mobile TV subscribers in the world in 2010, and the number of subscribers in our country will reach 40,000,000. Facing such a huge mobile and broadcast TV user groups, the network operators and equipment manufacturers in each country pay great attention to this service and hope it to be the new growth pole of mobile multimedia service. Therefore, compared with the related industries in China, mobile TV is a god-given opportunity for development and also a golden opportunity for independent innovation.
As an innovative multimedia service, the mobile TV's implementation is the result of combining several technologies, and in summary, there are mainly three technologies: downlink transmission technology, uplink interaction technology and service layer implementation technology.
The downlink transmission technology is the key point to implement this service, and it is responsible for transmitting the information and content of TV programs to the subscribers. This technology obtains a lot of attention in the industry, and there are a variety of methods for implementing this technology, and in summary, there are generally three kinds of methods for implementing different downlink transmission technologies: (1) the method based on the mobile network technology; (2) the method based on the satellite transmission technology; (3) the method based on the method for implementing the ground digital broadcasting network technology.
For the third method, the technology used in the implementation is based on the ground digital broadcast TV transmission technology, and the frequency in use is the broadcast TV frequency band. In order to adapt to the feature of mobile user equipment, some technologies are developed to be mobile TV technology based on the prior art, while some other technologies are designed for both ground digital broadcast TV systems and mobile TV systems. This kind of technologies receive much more worldwide interest and also has the most number of schemes, whose typical technologies comprise DVB-H in Europe, MEDIAFLO in USA, T-DMB in Korea and ISDB-T in Japan etc. Wherein, the two technologies in occident are designed specifically for the mobile stations, while the two in Japan and Korea can be used in both mobile stations and digital TV. Tsinghua University and Shanghai Jiao Tong University in China have respectively studied the technology in China based on the digital TV standards, such as DMB-TH and ADTB-T. In addition, Beijing Nufront Technology Co., Ltd also developed one ground mobile multimedia broadcast technology T-MMB on the basis of the DAB technology in Europe.
The data information included in the mobile multimedia broadcast electronic service guide (ESG) message mainly has: service information, service extension information, content information, service parameter information and arrangement information. How to flexibly use the service channel to multiplex and transmit ESG message is the problem to be solved at present.